From a7eb363ac1acb5566ce1af923d07c658361d5ad4 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Fri, 17 Oct 2014 21:37:38 +0200
Subject: [PATCH] win32: make lseek() fail on pipes

On MingGW seeking on pipes succeeds.

This fix is quite similar to Gnulib's (lib/lseek.c).
---
 osdep/io.c | 11 +++++++++++
 osdep/io.h |  8 ++++++++
 2 files changed, 19 insertions(+)

diff --git a/osdep/io.c b/osdep/io.c
index 819cdcbf69..b93618400c 100644
--- a/osdep/io.c
+++ b/osdep/io.c
@@ -17,6 +17,7 @@
  * You should have received a copy of the GNU General Public License along
  * with mplayer2.  If not, see <http://www.gnu.org/licenses/>.
  */
+#define MP_HIDE_IO_REPLACEMENTS
 
 #include <unistd.h>
 #include <errno.h>
@@ -395,4 +396,14 @@ char *mp_getenv(const char *name)
     return NULL;
 }
 
+off_t mp_lseek(int fd, off_t offset, int whence)
+{
+    HANDLE h = (HANDLE)_get_osfhandle(fd);
+    if (h != INVALID_HANDLE_VALUE && GetFileType(h) != FILE_TYPE_DISK) {
+        errno = ESPIPE;
+        return (off_t)-1;
+    }
+    return lseek(fd, offset, whence);
+}
+
 #endif // __MINGW32__
diff --git a/osdep/io.h b/osdep/io.h
index ae3cdc1802..a24ad7c231 100644
--- a/osdep/io.h
+++ b/osdep/io.h
@@ -77,6 +77,7 @@ int mp_closedir(DIR *dir);
 int mp_mkdir(const char *path, int mode);
 FILE *mp_tmpfile(void);
 char *mp_getenv(const char *name);
+off_t mp_lseek(int fd, off_t offset, int whence);
 
 typedef struct {
     size_t gl_pathc;
@@ -105,6 +106,13 @@ void mp_globfree(mp_glob_t *pglob);
 #define tmpfile(...) mp_tmpfile(__VA_ARGS__)
 #define getenv(...) mp_getenv(__VA_ARGS__)
 
+// Things MinGW defines as macros, and which we want to override only for the
+// user, and not io.c (which wants the original definition).
+#ifndef MP_HIDE_IO_REPLACEMENTS
+#undef lseek
+#define lseek(...) mp_lseek(__VA_ARGS__)
+#endif
+
 #ifndef GLOB_NOMATCH
 #define GLOB_NOMATCH 3
 #endif